Start by slicing the chicken breast into thin pieces for quick cooking. Chop the vegetables - onion, green beans, carrot, and bell peppers - and set them aside in a bowl.
In a wok or large skillet, heat the 2 tablespoons of oil over medium-high heat until shimmering but not smoking.
Add the minced garlic to the hot oil and sauté for about 30 seconds until fragrant.
Add the sliced chicken breast and stir-fry for about 5-7 minutes, or until cooked through.
Add the onion, green beans, carrot, and bell peppers, stir-frying for an additional 3-4 minutes until the vegetables are tender but still crunchy.
Stir in the Thai roasted chili paste, sweet soy sauce, and fish sauce, mixing everything well.
Taste and adjust the seasoning, adding more sweet soy sauce or chili paste as desired, then stir-fry for another minute.
Remove from heat and serve immediately, pairing with steamed rice or noodles.
